PHOTOS: Happy Anniversary, Man on the Moon

Friday is 38 years since man's first steps on the moon.

Apollo 11 Anniversary: 'Giant Leap for Mankind'

It's been estimated that a sixth of the world's population watched as Apollo 11 landed and Buzz Aldrin and Neil Armstrong walked on the moon. Aldrin poses for a photograph taken by Armstrong beside the U.S. flag on the moon. (NASA )